By Julie Bycowicz

WASHINGTON (AP) --

The Rio Olympics are in full swing: Michael Phelps is back to winning races in the pool, Simone Biles is running up the score in the gym and Hillary Clinton is advertising with eyes on doing just as well on Election Day.

Donald Trump isn't even competing.

The Democratic presidential nominee is airing $13.6 million in campaign commercials during the Summer Games, seeking to reach the millions of television viewers who can't skip past the commercials as they watch live coverage of the Olympics.

She has the audience to herself, as Trump has yet to air his first paid TV ad of the general election campaign.

It's a striking change from four years ago, when then-cash-strapped Mitt Romney and his allies scrounged up the estimated $18 million needed to match what President Barack Obama was spending to advertise during the three weeks of the London Games, according to Kantar Media's political advertising tracker.

While Trump's campaign has requested advertising rates from stations in key states, including Florida, the Olympics are quickly slipping beyond his reach. The opening ceremony was Friday and this week features some of the most popular sports, including swimming and women's gymnastics.

"I'd love to know what they're waiting for," said Will Ritter, a Republican ad maker and veteran of Romney's presidential bids. Trump's eschewal of political norms such as advertising "cannot survive the professionalized deconstruction that Hillary is doing every day," he said.

As anyone watching the games can attest, Clinton's advertising is as omnipresent as NBC's commercial breaks. Her spots appear alongside those of corporate behemoths such as McDonald's and Chevrolet.

Over the first three weeks of August, Clinton is spending $8 million on the national NBC network, which carries the games, and at least another $4.5 million on local NBC affiliates, an Associated Press analysis of Kantar Media data found. The campaign is also spending another $1.1 million on NBC's cable channels Bravo, USA and MSNBC.

One Clinton ad in heavy rotation is an awkward clip from David Letterman's late-night talk show. In it, the host holds up Trump shirts and ties and points out that they were made in Bangladesh and China, not America. To that, Trump smiles sheepishly.

The commercial ends with the text: "He's outsourced jobs to 12 countries." And it digs at his campaign slogan: "Make America great again."

Clinton is following Obama's Olympics playbook. The president debuted several commercials during the games in 2012, including one during the ratings-heavy — and expensive — opening ceremony. His spots were a mix of positive messages about his presidency and his contrasts with Romney.

Romney and his allies also took advantage of the games. But the GOP nominating convention was still weeks away when the London Games began, putting money he raised for his general election campaign out of reach.

The pro-Romney super political action committee Restore Our Future aired an ad featuring Olympic athletes talking about Romney's business sense. He was tapped to run the 2002 Salt Lake City winter games, the first after the Sept. 11 terrorist attacks.

"We made the determination the Olympics offered a large, captive audience who weren't channel surfing," former Restore Our Future leader Carl Forti said. "And in the case of Mitt Romney, we had a candidate who turned around the Salt Lake Olympics and had a unique story to tell."

Although neither Trump nor Clinton has as personal a connection to the Olympics, presidential candidates usually cannot resist the ratings bonanza, even if the ads come at a higher cost. Trump isn't short on funds, having announced recently that he and his Republican allies raised more than $80 million last month.

Asked about Trump's decision to stay off the air, Trump's spokeswoman Hope Hicks said the campaign was not yet ready to provide details about its TV advertising strategy.

There are a few pro-Trump groups doing a relatively minor amount of advertising.

Rebuilding America Now is spending about $2 million in the first three weeks of this month, but has nothing on the national NBC network. Its spending is concentrated on national cable and in four states: Florida, Ohio, North Carolina and Pennsylvania, Kantar Media shows.

The NRA's political arm also has $1.3 million in anti-Clinton spots up during the same time period — but again, not on the national NBC network.

Steve Duprey, a Republican national committeeman from New Hampshire, conceded that Trump is missing a chance to connect with millions of voters. He suggested it may not matter.

"While the decision not to have big ad buy during Olympics is unconventional," he said, "I'm not sure conventional rules apply."

Associated Press writers Steve Peoples, Chad Day and David Bauder contributed to this report.

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